Flotation machine



oct. 6,1925- athen,

Oct. 6, 1925- l A. C. DAMAN I LoTATIoN MACHINE -Fiied om. 18'. 1923- 3 sheetrs-sheet` 2 d Noz nu,

A. C. DAMAN FLOTATION MACHINE Oct. 6, 1925.

-m'ed oct. 18

. 1923 3 Sheets-Sheet 5 Patented Oct. 6, 1925.

UNITED ySTATES PATENT OFFICE.

.ARTHUR C. DAMIAN', 0F DENVER, COLORADO.

rLoTATIoN MACHINE.

Application led October 1851923. Serial No. 669,326.

-To all whom t may concern.' g Be it known that I, ARTHUR C. 'D aMAN, a citizen. ofthe United States, residing at Denver, in they county of Denver and State -coarser material or' sands and that. in order to recoverthe valuesI from the slimes, the entire pulp' content must be subjected to several 'stages of retreatment.

The principal object of the present invention ,is to provide a machinein which any portion of the pulp (more particularly the slimes) may be subjected to retreatment without it being necessary to retreat the entire pulp content of the machine. In this machine the slimes may be repeatedly passed through a given cell and given anextended treatment while the sands are independentlypassed directly after treatment to the next cell or to the tailings.

Another important object of the inve-n tion isrto so construct the 'machine that the feed chamber will be materially lower than the frotlning and settling chamber so that the tailings from each cell I:will {iow by gravitv into the feed chamber of the next succeeding cell-the difference in elevation being made great enough soy that the pulp feeding back into the feed chamber will fall or cascade, thereby assisting in the agitation and aeration.

' Other objects are:

To provide a machine of this character which the pulp will beagit-ated and emulsified and forced in sheet like form upon the surface of the v liquid in the frothing` cham- 'ber' by an independent mechanical impeller for each cell, said impellers being so ar ranged that there will be no stuiiing. boxes pli' other wearing surfaces below the pulp me' -z v 'I To provideV means whereby the height from which the pulp is discharged upon the surface ofthe liquid can be regulated and adjusted;

To construct a machine in which 'a part 0r all of either the settling gangue, overflowing tailings, or suspended concentrates, from each flotation chamber may be passed for retreatment through the same c ell or bypassedv for further treatment to the next cell. and to provide means for making any of these adjustments independently;

To provide means whereby the gangue. Aand tailings from veach cell will be eiciently and thoroughly re-emulsified and reaerated before-again being passed to the 4fiotation chamber and in which fresh dotation agents mav be added before each re-emulsification;

To provide a machine in which the otation chambers of each cell can be put into open communication at the froth line to allow a free flow of-froth from cell to cell and maintain a. uniform liquid level throughout the machine To provide means fon causing the liquid level in the feed chambers to be lower than that of the flotationk chambers so that the surface level in the flotation chambers will not be effected by any variation of level in the feed chambers;

To provide means for adding air to the pulp in addition to that provided vby the vortex of they impelle-r.

Other objects and advantages Areside in thev detail construction of` the invention which result in simplicity, economy and vefficiency and which will become more apparent from the following description.

In the following detailed descriptlon of the invention reference is had to the accom Y panying drawings which form a part hereof. Like numerals refer to like parts inK all views ofthe drawings and throughout the description.

In the drawings: I

Fig. A1 is a plan view of a four cell embodiment of the invention. the cells being numbered from left to right 1, 2, 3, and 4, respectively,-cell 3 being shown in section taken on the line 3 3, Fig. 2, and cell4 being shown in section taken on the linev 4 4. Fig. 2.

Fig. 2 is a vertical cross section taken on the line D D, Fig. 1., Y.

Fig. 3 is an elevation of the froth die weir guard shown in Fig. 6.

charge side of the invention, partly in section, the sections being taken as follows: Cell 2, line A-A, Fig 2; cell 3, line B-B, Fig. 2; cell 4, line C-C, Fig. 2.

Fig. 4 is a flow diagram of the machine, the direction o-f flow being shown by the arrows. The dotfted arrows indicate the mineral o-rconcentrate, the dash-dot arrows the fines or slmes; and the solid line arrows the coarse orsands.

Fig. 5 is a detail view of vone of the cell partitions showing how it might be cut away to allow free passage between fiotation` chambers at the froth line.

Fig. 6 is a detail view of the Weir guard used in the invention.

Fig. 7 isa vertical section through the Fig. 8 is a detail cross section of the gangue return passage.

Fig'. 9 is a detail cross section through the froth deflector.

The machine may comprise any desired number of cells, four being shown. Eachcell comprises a feed chamber 10 separated from a froth chamber 11 by means of a lift chamber 12. The sides and bottom of the froth chamber 11 depend inwardto a semi-pointed bottom against the wall of the lift chamber 12. An oblique sand discharge pipe 13 connectsthe bottom of the froth chamber with the feed' chamber 10. A hinged gate valve 14 provided with an operating rod 48 controls the opening of the pipe 13 in the chamber 10, and a plug 15 controls the opening thereof in the chamber 11. The plug 15 is -operated by means of an operating rod 16, by means of which the plug may be forced entirely through the pipe 13 to clear it, should it become clogged.

The feed chamber 10 is provided with a false bottom 17,'having a concentric opening 18, and beneath which is arranged an lmpeller 19. Impeller 19 is carried on the extremity of a shaft 20, which is supported in the feed chamber in bearings 21, and

which is provided with a belt pulley 22 by means of .which it is driven. It will be 'noted that all bearings on the impeller shaft 20 are above the How of the pulp so that they will not be injured by sand and grit.

That part of the feed chamber below the false bottom 17, is in open communication with the lift chamber 12 at one side and is rounded at. the opposite side as shown aty 23, Fig. 1, to conform to the throwof tbe impeller 19. The lift chamber 12, terminates at its upper extremity in a froth deflector 24. shown in detail in Fig. 9, which telescopes into the upper opening of the lift chamber 12. The froth deector may be raised or lowered as desired, ,byslidng itin and out of the lift chamber, and is held at any desired height bymeans of a' thumb nut and bolt 25 which travels in' a slot 26 inv the'froth shield 24. The froth deflector 24 is provided with a`hinged apron 27 which may be adjusted, by means of ,a

thumb screw 28, to regulate the angle of' der a weir guard 31, over an adjustable gate 32, through a weir opening 33 in the intercell partition Sand into a return trough 34.

The weir guard 31 is of special construction having an opening 35 dwhich may be adjusted by means of a sliding gate/36, so as '85 to allow a portion of the surface flow to pass thru the Weir opening 33. The height of the weir gate 32'maybe adjusted by means of thumb nut 37 so as to maintain the pulp level at any desired point.

The weir overflowfrom the final cell in to the next. succeeding cell.- The pipe 40.

from the last cell of the series carries the sa-nd away to the tailing'dump.

A perforated air plpe 42 1s positioned in each lift chamber 12, and fed from a riser 43, which is controlled by a valve 44. The risers 43 are fed froma common-air main 45 above the machine..

In some installations of the machine it is preferred to have an open cell to cell'flow at the froth line in the froth chambers 11, thereby allowing thesuspended material to How directly from one frothing chamber to the series is carried away in a tailings.

the next, without being againvagita'ted and aerated, and serving to maintain an even liquid level throughout the entire machine. .To accomplish this an opening 46,(see Fig. 5) is formed in the intercell partition betweeneach froth chamber extending below the liquid level (shown in broken line at 47l of the cells.

, In operation the pulp is fed into the feedately sets the mass to whirling around the shaft 20, and forms a vortex, as shown in broken lines in Fig. 2, into which the whirling pulp and air is sucked through the opening 18 into theimpcller chamber below the false bottom 17 .i It will be noted that the feed chambers are rectangular, the whirling mass of pulp being violently and constantly brought against the flat sides of the chamber causing a very violent agitating and mixing action. which results in bringing the mineral particles into intimate contact with the reagents, and the suspended air particles, making an efficient emulsion of the entire mass. The pulp is forced from the impeller b v centrifugal force up the lift chamber 12,' where additional air may be added, if neces? sary, by the perforated pipe 42. Practically no pressure need he maintained in the pipe 42, since the air doesno lifting of the pulp. The pulp in rapidly moving past the pipe creates a partial vacuum above the pipe that will draw out the air. This feature results in a great saving in power since a high air pressure is unnecessary. f

The pulp with its entrapped air Hows into the deflector 24, 'and is defiected onto the surface of the liquid in the froth chamber in a wide sheet. v f

Successful fiotation depends upon a delicate balance of small forces. The angle at which the mineral particles are presented to the surface of` the water must be just right in order to insure maximum flotation. In this invention not only the angle of the presented froth may be changed, but the height from which the pulp is dropped, Vmay be adj usted in' order to obtain just the proper balance to separate the class of ore being treated.

The froth with its suspended mineral flows across the froth chamber and is scraped into the launder 3() by the Scrapers 39.

The sand settles to the bottom and may be all returned to the feed chamber of cell No.

1, for retreatment, through the pipe 13, or a portion by-passed to the feed chamber'of cell No. 2 through the pipe 40.

The slimes remainmg suspended in the solution pass into the trough, and may be all returned to the feed chamber of cell No. 1 for retreatment, through the outlet 38, or a portion may be allowedv to pass to cell 2, thru the outlet 39.

The action in the remaining cells'is of course similar to that of cell 1 scribed.-

lf a test discloses the slime tailings to still contain Yan appreciable amount of values,

the gates 38 are opened and the gates I39 closed .until the proper recovery from the slimes is obtained,

If a test discloses the sands in the earlier cells to be practically barren, the pipes 13 are closed by the plugs l5 and the values41 opened, to speed up the passage of the sands through the machine. This results in a decided increase in efficiency since it rapidly the feed chambers 10. Should it be-desired' to shut down any cell, the valve 14e is closed,V

and lnpeller 19 stopped, and the gates 54 opened. The feed chamber will now fill to the openings 53, and the material from the preceding cell will flow through the feed chamber to the next succeeding cell without disturbing the action of the remaining cells;

Should it be found in certain ores that the concentrates are -not clear, the slidesr36 of the Weir guards 31, may be opened slightl)7 to allow a percentage of the concentrate in each cell to flow back to the feed chambers and be subjected to retreatment. This will result in an increase in the value of the concentrate.

While a specific form of the improvement has been described and illustrated herein, it

is 'desired to be understood that the sameV ing onto the top ofthe latter; a passage feeding hack by gravity-from the bottoml of said froth chamber to said feed chamber; a`

false bottom inl said feed chamberY having a concentric. opening, said feed chamber being open to said lift chamber below said false bottom; a shaft supported above said feed chamber and extending vertically through said opening and an impeller secured on said shaft below Ysaid false bottom for forcing .pulp into said lift chamber. v v

2.' A flotation machine comprising in combination a feed chamber; a froth chamber, said feed chamber extending below said froth chamber; a lift chamber, said lift chamber being interposed between said feed chamber, and said froth chamber, and feeding onto the top of the latter; a false bottom in said feed chamber having a concentric opening, said feed chamber being open to said lift chamber below said false bottom; a shaft supported above said feed chamber and extending vertically through said 'opening and an impeller secured,on

said shaft below said false-bottoml for forccombination of aa passage in each cell com-l ling thefeed chamber openings.

4. In a fiota'tion machine comprising a vseries of cells each consisting offa feed chamber, a lift chamber, and a froth chamber, thel combination of -a trough in each cell communicating with the froth chamber near the solution level and opening to the feed chamber of that cell and to the feed Chamber of next adjacent cell and having gates control- Y ling the feed chamber openings; a passage 1,55eLoss in each cell connecting the bottom of the froth chamber with the feed of that cell and a second passage'connecting the bottom of said froth chamber with the feed chamber of next adjacent cell, said passages having gates controlling their openings.

5. In a flotation machine, a froth chamber; a Weir in the wall ofl said chamber; an open bottomed Weir guard arranged in front of said Weir and extending below the liquidv surface in saidchamber there being an adjustable opening in said guard arranged to control the Vsurface flow to said Weir.

In testimony whereof I ax my signature. Y

ARTHUR o. DAMAN. 

